Sulfur transfer agent production wastewater recycling method

Abstract

The present invention provides a sulfur transfer agent production wastewater recycling method, which comprises: adding sulfur transfer agent fine powder as a co-precipitating agent to sulfur transfer agent production wastewater to obtain a mixed suspension, wherein the adding amount of the sulfur transfer agent fine powder is 1-15 g / l by adopting the wastewater volume as the reference; controlling the pH value of the mixed suspension at 2-6; carrying out first-stage solid liquid separation treatment on the mixed suspension with the pH value of 2-6 to obtain a first-stage clear liquid and a first-stage heavy phase and / or precipitation residue; and carrying out second-stage solid liquid separation treatment on the first-stage clear liquid to obtain a second-stage clear liquid and a second-stage heavy phase and / or precipitation residue, and conveying the obtained second-stage clear liquid to a sulfur transfer agent production process so as to be recycled. According to the present invention, the sulfur transfer agent fine powder is adopted as the co-precipitating agent, and the sulfur transfer agent production wastewater and the rare earth elements in the sulfur transfer agent production wastewater can be recycled, such that the resources are recovered, and the environmental pollution is reduced.

Description

Technical field [0001] The invention relates to a method for recycling waste water produced by a sulfur transfer agent. Background technique [0002] In the fluidized catalytic cracking (FCC) reaction process, the feed oil and the catalyst are quickly contacted in the riser to carry out the catalytic cracking reaction. The coke produced by the reaction is deposited on the catalyst and the catalyst is deactivated. After being stripped, it enters the regenerator for coking regeneration. During the regeneration process, the sulfur-containing compounds deposited in the coke are oxidized to form SOx, which is discharged into the atmosphere with the regeneration flue gas, causing environmental pollution. [0003] The use of flue gas SOx transfer aid (also known as sulfur transfer aid or sulfur transfer agent) is the main technical measure to control the SOx emission of the regenerated flue gas of the FCC device. Its working principle is that the SOx generated in the flue gas is capture...

AI Technical Summary

Problems solved by technology

[0005] Because the sulfur transfer agent contains a variety of metal components that are easy to pollute the FCC catalyst, its production wastewater cannot be reused in the production of FCC catalyst

Even if the waste water is reused in the production process of the sulfur transfer agent itself, if it is directly recycled online without treatment, there will be the following problems: (1) if it is reused to prepare the rare earth impregnation solution, the fine particles and rare earth flocculation and precipitation contained therein will Continuous accumulation will cause the filter cloth mesh to be gradually blocked, and the filtration efficiency will be greatly reduced; (2) If it is reused in the gel forming process, when the colloid spray is formed, the solid particles contained will not only easily wear the atomizing nozzle of the spray drying tower, but also Adhesion with colloid results in poor sphericity of additive particles, which affects wear resistance

[0009] In the above-mentioned prior art, the production process and composition characteristics of sewage are significantly different from those produced by sulfur transfer agents, and the operation is relatively complicated, and more substances such as flocculants and chemical precipitants are required, and the solid-liquid separation efficiency is not high enough.

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